I tried to replicate this with the same filter on resource (location.city=Munich) and it does work as expected.

Hi, thanks.

If I do the same, as example, one filter: (location.City + is + Munich) and another one: (location.City + is + Frankfurt) and apply both at same time, I get no data in PSO.

For me it works applying one or the other,  but not both at same time.

But that’s what I would expect (otherwise applying more filters would give you more results, which doesn’t make sense), those two separate filters will be combined with AND, returning no results. If you want OR you need to put it into a single filter.

Thanks again. 

Actually I would like the result of the logic to be “AND” so it would add results to my filtering. .
As a Resource planner, as an example,  if I have whole Germany resources. For operational reasons, I want to view together locations A&B, then C&D, then A&F… etc. 
So I can’t. I need to apply filters one by one. Of course I can make combinations of locations in single filters. But imagine If I have 10 locations, how many combinations of filter I’d need to do in order to have in hand when needed.
Thanks for the quickly reply. 

In natural speech you would indeed say AND, however from a logic point of view what you need is OR. location.City=Munich AND location.City=Frankfurt will never be true. I understand your use case, however separate filters will always be AND-combined.