Template Variables for Data Link URIs

I’d like to use a multi-value template variable to link to another dashboard, but the format needs to be something like &var-tempvar=a&var-tempvar=b&var-tempvar=c, however {tempvar} returns {a,b,c}. There doesn't seem to be a template variable format that will allow this extrapolation. If I use {__all_variables} it goes through just fine, however, so I’m not sure why using one of the template variables can’t respond in the same way. I’m using version 7.1.5.

Anybody? I’m really stuck here.