Filtering values only currently present in fact tables

Hi all! 

the situation: there are two fact tables allocation and demand. when a role is required in a team, it is inserted in the demand table; when a role is allocated to a team, it's in the allocation. 

in the report view, i have a clustered column chart. x-axis: Months; y-axis values for demand/allocation. 

I also built a bridge table for allocation and demand, containing all historical values for roles per team. This Bridge table is connected with one-to-many to the fact tables with the key. Also, this bridge is used for two slicers in the report: team and role. When i pick a team, the roles slicers displays all historical roles of that team. 

What I need is to display only those roles, that are currently assigned/demanded in the fact tables, and not all historical roles. 

I know it's not much, but I'm going to leave a screenshot of the sample set so you have an idea. 

i'd greatly appreciate any help!