@jonatandor35 This was my problem. I always tried it —> with <— the dot. Damn! 
I already was searching many times for exactly this solution one, because i am often in this situation, try to make my code much more flexible and it was always this little one missing knowlegde, which made my coding make difficult.
I have a " deja-vu "! Last time i think it was also you, when you showed me a new coding-technique and i said —> " right now i am going to upgrade my coding-style "
The result was the beginning of my SUPER-FILTER-ENGINE, now i can hoppely improve it even much more, by using this new coding-knowledge.
So keep in mind → every little extra-tip made by you, blows up my project a lot!
Thanks for this!
P.S.: I could integrate already some new coding skills → the first sign of life of the “DB-SWITCHING-FUNCTION” can be seen here…
https://www.media-junkie.com/pflegeservice
And one day, you will see the end-result and all the integrated features of my SUPER-FILTER-ENGINE 
.
See you my friend.
EDIT: At the current state, i just have 2-fixed integrated EXAMPLE-DATABASES in this example:
- Data-Collection: —> “Worlds-Presidents”
- Data-Collection: —> “Team”
But i think you will recognize by yourself what i am trying to accomplish 
(I’m tired of creating every time a new filter with CODE over and over again for several pages. Soon this will work for all my sites 
)