I am trying to combine sets from several data sources but while some sets can be combined, other can't as the option isn't shown on the left click menu. The sets contain a list of product items from a dimension value. What I am trying to achieve is to reveal the share of unique items on a data source b compared to the other data sources (ie: company X has 35% exclusive products compared to peer group). So either a) there is a better approach to solve my problem, or b) I have a problem with my data.
Only some sets can be combined, other don't have the option shown on left-click:
List of items in sets:
Thanks for your help!