Concatenate rows values based on filter context

Hi,

I am trying to capture the values selected in a slicer so I can display a notification on screen such as "You have selected the following: A, B, C).

For displaying if a single value is selcted, I am using the following:

HasOneValue =
"You have selected the following Territory filter: "
    & IF (
        HASONEVALUE ( Rev[Territory] ),
        ALLSELECTED ( Rev[Territory] ),
        " More than one territory")
    )

However, for the second part of the if statement, I would like to show the actual unique values selected in the slicer concatenated together (e.g. "You have selected the following Territory filter: Territory 1, Territory 2"). I tried using concatenatex, and this works...too well! It passes in every value from every row that matches my filter context. I next tried wrapping the column I want to return with DISTINCT, as follows:

HasOneValue =
"You have selected the following Territory filter: "
    & IF (
        HASONEVALUE ( Rev[Territory] ),
        ALLSELECTED ( Rev[Territory] ),
        CONCATENATEX ( rev, DISTINCT ( Rev[Territory] ), "," )
    )

However, this returns an error inside the visual, although the DAX code itself does not show an error when run. 

Any thoughts as to how to fix this?

Thanks,

Scott