Dynamic Meaure using Multiple Selection of Input Control

Good Afternoon,

During the development of a Web I report, I have used, in one of the input controls, the function ElseIf to make a Measure Selector, using the formula

=If ReportFilter([Select a Measure]) = "Capacity" Then [Cap]

ElseIf ReportFilter([Select a Measure]) = "Eficiency" Then [Eff]

ElseIf ReportFilter([Select a Measure]) = "Margin (%)" Then [Margin (%)]

ElseIf  ReportFilter([Select a Measure]) = "Order Quantity" Then [Order Quantity]

But it only allows me to select 'Single Selection filters', as the picture shows.

I´d like to select, for example, Capacity and Efficiency and show them at the same time.

Can anyone help me? Thanks in advance!