TM1Member will allow you to use parameterized references by using cube values as part of the query itself. For example if a UserParams cube was created with the }Clients dimension (thus allowing concurrent usage by all users) which would hold various choices made by users as they used your application, then dynamic subsets could use those choices as part of their syntax, thus altering not just the thresholds for comparisons (we can see elsewhere in this document how to check if something is, say, above a certain threshold which is actually a value in another cube) but the actual thing that is queried in the first place.

For example, this shows the descendants of a parent member, the name of which is held in the 2D UserParams cube at the intersection of the current username and ‘SelectedParentDimix’.
{DESCENDANTS(TM1Member(
TM1SUBSETALL( [Product] ).Item([UserParams].(StrToMember("[}Clients].["+USERNAME+"]"), [UserParamMeasures].[SelectedParentDimix])-1)
, 0)) }

Below are screenshots showing the parameter cube which can be extended to hold various user-specific selections and then link them into dynamic subsets plus the other relevant screens.