Use values from a record to determine a data source

Hi there

I have an object, A, which is connected to both a user and another object, 'Organisation'.

I've built functionality so that when accessing the home page, a user is prompted to select the organisation view they wish to see from a dropdown list of all organisations.

From here they should be redirected to a dashboard with a table, showing all records for object A that are related to them and that organisation.

Object A, is always associated with an organisation via a field 'Organisation'.

Object A also has a field 'Original User's Current Organisation', which is populated with the result from the dropdown on the homepage.

How can I edit the data source that populates my dashboard table to only show records where 'Original User's Current Organisation' and the object's 'Organisation' are a match?

In the 'Data Source' section of the table's settings I want to add a rule like:

Match all of the following:
Organisation is the same value as User's Current Organisation
Is there a way to do this or would somebody be able to suggest a more effective way of setting up this 'Context Switcher' from the beginning?
An alternative way may be something like, having the 'Current Organisation' saved on the User, but even in this case, I would need to be able to filter the data source by a value stored against the connected logged-in user, which doesn't seem to be possible?
Thanks in advance!