# How to restrict a multiple choice field based on parent connection? **URL:** \ **Category:** Get Answers\ **Created:** [June 2, 2026, 6:41pm UTC](https://forums.knack.com/t/how-to-restrict-a-multiple-choice-field-based-on-parent-connection/20415 "2026-06-02T18:41:37Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![JDWorleyKY](https://avatars.discourse-cdn.com/v4/letter/j/9de053/32.png) [@JDWorleyKY](https://forums.knack.com/u/JDWorleyKY)\ **Post date:** [June 2, 2026, 6:41pm UTC](https://forums.knack.com/t/how-to-restrict-a-multiple-choice-field-based-on-parent-connection/20415/1 "2026-06-02T18:41:37Z")
I’ve struggled with this for a while, so I thought I’d pick the Masters brains here to see if you all know a way. In my inventory system, I create Purchase Orders regularly for different Vendors. I first select the Vendor (Manufacturer), then I add Products to the Purchase Order. How can I only show Products that contain this Vendor in the multiple choice list? ![Screenshot 2026-06-02 at 2.33.13 PM](https://us1.discourse-cdn.com/flex020/uploads/knack/original/2X/6/6f8da1471aa2791ec8569b3a7ade31d4539e102e.png) This image shows the Vendor already at the top, from the Parent page of the Form. But it shows ALL Products from the Products database. Each Product is connected to one Vendor, so you’d think there’d be a way to restrict this to only show those? Perhaps I need to somehow connect Product to the Vendor? Since Vendor is in the main PO, but the Product is in the “PO Line Items” table? ![Screenshot 2026-06-02 at 2.38.53 PM](https://us1.discourse-cdn.com/flex020/uploads/knack/original/2X/e/ec4e9524258f46b2375db61c8a717db821597c50.png) -- ![Screenshot 2026-06-02 at 2.39.52 PM](https://us1.discourse-cdn.com/flex020/uploads/knack/original/2X/9/973da3c59d1108bf3a6f23d8c9475ef8895ae042.png) ---
**Author:** ![ivan](https://sea2.discourse-cdn.com/flex020/user_avatar/forums.knack.com/ivan/32/1019_2.png) [@ivan](https://forums.knack.com/u/ivan)\ **Post date:** [June 2, 2026, 7:32pm UTC](https://forums.knack.com/t/how-to-restrict-a-multiple-choice-field-based-on-parent-connection/20415/2 "2026-06-02T19:32:14Z")
If you change the Vendor from a multiple choice field to a connection field to a new Vendor object, then you’ll be able to filter the Products dropdown to the Vendor that the current PO is connected to. Let me know how that goes! ---
**Author:** ![JDWorleyKY](https://avatars.discourse-cdn.com/v4/letter/j/9de053/32.png) [@JDWorleyKY](https://forums.knack.com/u/JDWorleyKY)\ **Post date:** [June 3, 2026, 2:32pm UTC](https://forums.knack.com/t/how-to-restrict-a-multiple-choice-field-based-on-parent-connection/20415/3 "2026-06-03T14:32:44Z")
The problem is the Vendor is connected to one Object - “Inventory PO”, but the Products go into a sub-Object called “Inventory PO Line Items”, which isn’t connected to the Vendor. I created the Vendor object and connected it to the Inventory POs, but its still not showing as an option to filter by. I have the Products object connected to Vendors now too. ![Screenshot 2026-06-03 at 10.32.20 AM](https://us1.discourse-cdn.com/flex020/uploads/knack/original/2X/4/4fee7ac8c7a1522203bf27f5aba40165c3caa2e9.jpeg) ---
**Author:** ![ivan](https://sea2.discourse-cdn.com/flex020/user_avatar/forums.knack.com/ivan/32/1019_2.png) [@ivan](https://forums.knack.com/u/ivan)\ **Post date:** [June 4, 2026, 6:08pm UTC](https://forums.knack.com/t/how-to-restrict-a-multiple-choice-field-based-on-parent-connection/20415/4 "2026-06-04T18:08:08Z")
If possible, can you create a simple entity relationship diagram between Vendor, Inventory PO and Inventory PO Line Items? Or, alternatively, describe each connection between each object in terms of one-to-one, one-to-many, many-to-one, or many-to-many. That should help figure out why you’re not seeing the option to show Products connected to the Vendor. Also would be great to see the Source of the Add Inventory PO Line Item form (the form is adding an Inventory PO Line Item connected to…?). ---
**Author:** ![JDWorleyKY](https://avatars.discourse-cdn.com/v4/letter/j/9de053/32.png) [@JDWorleyKY](https://forums.knack.com/u/JDWorleyKY)\ **Post date:** [June 8, 2026, 8:47pm UTC](https://forums.knack.com/t/how-to-restrict-a-multiple-choice-field-based-on-parent-connection/20415/5 "2026-06-08T20:47:51Z")
All of the Connections are One-to-many. Vendors, Products, Inventory POs, and Inventory PO Line Items are all connected to each other. I even added the Vendors Connection field to the Inventory PO Line Items too, and re-made the form shown above to be: ![Screenshot 2026-06-08 at 4.45.26 PM](https://us1.discourse-cdn.com/flex020/uploads/knack/original/2X/d/d38d50d32aea68a9a768569c8beef1dc445fe4d5.png) but I still can’t get the Products to be filtered down by Vendor. Diagram: ![Screenshot 2026-06-08 at 4.46.45 PM](https://us1.discourse-cdn.com/flex020/uploads/knack/original/2X/4/44df801abc830ed8f12463b3d6a7f667d9da4dcf.jpeg) Any other ideas? Thanks!! ---
**Author:** ![JDWorleyKY](https://avatars.discourse-cdn.com/v4/letter/j/9de053/32.png) [@JDWorleyKY](https://forums.knack.com/u/JDWorleyKY)\ **Post date:** [June 10, 2026, 4:43pm UTC](https://forums.knack.com/t/how-to-restrict-a-multiple-choice-field-based-on-parent-connection/20415/6 "2026-06-10T16:43:15Z")
Solved by Sunny! He added the Vendor choice on the Form, but hid it. This allows to only show products connected the form’s Vendor. ![Screenshot 2026-06-10 at 12.40.45 PM](https://us1.discourse-cdn.com/flex020/uploads/knack/original/2X/a/a9c625eadca583392e65d80e2339564eed934978.png) ---
**Author:** ![Sunny\_Singla](https://sea2.discourse-cdn.com/flex020/user_avatar/forums.knack.com/sunny_singla/32/1007_2.png) [@Sunny\_Singla](https://forums.knack.com/u/Sunny_Singla)\ **Post date:** [June 16, 2026, 4:06pm UTC](https://forums.knack.com/t/how-to-restrict-a-multiple-choice-field-based-on-parent-connection/20415/7 "2026-06-16T16:06:47Z")
Thanks @JDWorleyKY