CV with combo box based on Member List Parameter not working

I have a CV that has annotation accounts in the columns and flow members in the rows. One of the columns has a combo box that should display all flow members except the flow member on the row that you are on. this is done by using a Member List parameter that runs a br function to get a full list of flow members and then exclude the flow member on the row the user is on. I cannot figure out how to pass the flow member of the current row to the parameter. Following is the code in the parameter. i've tried PovFlow, CvFlow, and MFFlow and none of these work. Any thoughts on how to get this to work?

F#Root.CustomMemberList(BRName=Dynamic_Member_List, MemberListName=[PB_Flow_BaseMods], selectedMember=[|MFFlow|])

I have this working in a different configuration where i get the flow member from one cv and pass it to a second cv using a navigation link parameter. In this configuration, i select a row in CV1 and pass the flow from CV1 to CV2. this way CV2 returns only the accounts for the one flow member in CV1 and the parameter returns a list of all flow members except the one selected in CV1.