When browsing through the site access list in the Page Builder there is no issue at all.
content.tree_root.location_id is taken into consideration properly and "switches" Content based on the Content's Location ID if this Location is out of scope for certain Site Access.

The problem occurs when the last viewed/edited Site Access is stored in the session. Then if the Content is out of SA scope and we edit it in the Back Office (pencil Edit button) it will be still edited under this last "remembered" site access, which is incorrect.

Steps to reproduce:
1. Set ezplatform.yaml SA config as follows:

        site:
            languages: [eng-GB]
        random:
            languages: [eng-GB]
            content:
                tree_root:
                    location_id: 42 #or different but outside of "Home" scope

2. Go to the Page Builder and browse through site accesses -> click on random SA to make it stored in the session.
3. Exit PB and go to the Content Tree.
4. Now click on Content of Location above Location ID = 42 (so for example in v3.2 click on Ibexa Digital Experience Platform LP Content).
5. Click on Edit.

Result:

Editing:
http://localhost:8102/random/
in English (United Kingdom)

Please, note the invalid random Site Access - this Content is outside of the random SA scope, we shouldn't be able to edit it in random SA.

Expected result:

Editing:
http://localhost:8102/site/
in English (United Kingdom)

Valid SA should be chosen (so site SA in this case or any other "fitting").