How to connect a dynamic page to two different collections

I have been following the example in
https://support.wix.com/en/article/working-with-multiple-item-reference-fields
and tried to rebuild this, but with Locations and Activities instead of Movies and Actors .
My Locations collection would be the master collection in that sense. It is the focus of the dynamic page. So the activites, which are shown in a repeater, change with each item from the Locations collection.
In the Locations collection i have a field called activity reference. It is a multiple reference-field; linked to the respective items in the Activities collection. There is a reference field in my Activities collection which shows the linked item in the Locations collection.

Unfortunately i am not able to connect two collections to one dynamic page. And if i want to use filters for my collections on the page, the reference field is not there to be selected.

I am quite stuck here. I appreciate every answer.
Greetings.

Hi.

Please reach out to Wix Customer Care . They will be of great help. This forum is only for code related issues and discussions.

Good luck!