Hi @Stef1,
Welcome to the community 
You would need a Many to Many relationship to store them and filter the list with that property.
Check here : Multi-Select Dropdown issue (only last item selected works) - #3 by dilon_perera
Thank you
Hi @Stef1,
Welcome to the community
You would need a Many to Many relationship to store them and filter the list with that property.
Check here : Multi-Select Dropdown issue (only last item selected works) - #3 by dilon_perera
Thank you