Inclusive slicer

I would like to ask for your help with creating an additive slicer. Normally, slicers in Power BI filter the dataset, but I would like to make one of my slicers to function additively.

I have a table (Sheet 1) where certain Trial_labels are actually References (Reference_flag=1), while others have corresponding Set_of_trials (int field) assigned to them. 

Use case: A user first filters by Set_of_trials, then by Trial_label and Method. On the graph and table, they would also like to see selected References in addition to the Trial_labels included by previous filtering. Is it possible for the user to choose which References to add via a separate slicer, with those selections appearing in the graph and table in addition to previously filtered data by other slices.

The reference slicer does not affect any other slicers (only table and graph) while Method slicer affects reference slicer. 

What is the most efficient way to achieve this? Test data on link https://we.tl/t-mbcideqzPb