OR Conditions in Looker - a nightmare or am I just thinking wrong

[moebe]

The following problem:
I have a department. This department is responsible for several products.
Now I have to make a filter that should look like this in the sql:
where (company_department = ‘Department Name’ or product_owner = ‘Department Name’)
This has to be done in LookML, because this logic has to be valid for every Looker of this exploration and the users shouldn’t/can’t work with custom_filter.
At first I thought that this could not be that hard, but I can’t find a solution.

• Parameters do not work because the departments are defined regularly in the source system and we would not even be able to maintain this definition in our system.
• Templated filters don’t work either, because I can’t create an OR condition with them.
  Is there really no standard approach to solve the problem properly.
  Is looker really not able to handle OR conditions?