[TxMt] Possible to use tab triggers within snippets?

Say I have this snippet:

${1:function}(${2:param1}, ${3:param2})

using tab trigger: pairfun

(so this theoretical snippet writes the code to call a two argument function)

So I type "pairfun" and hit tab. type a function name. Hit tab. Now I want to fill my first parameter with the output of a snippet. If I want to use a tab trigger here, it won't invoke the snippet, but instead tabs to the second function parameter in the current snippet.

Is it possible to use another key combination to invoke a second tab trigger within a snippet? My current workaround is to finish tabbing through and then come back to fill in the parameter.