Tab-group don't work if there are a intermediate macro between tab-group and tab

[Josue-T]

How to reproduce

Put a code like this:

{{tab-group}}
{{velocity}}
{{tab title="Hello world"}}
my content
{{/tab}}
{{/velocity}}
{{/tab-group}}

Normally it's expected to work because the velocity macro will just return the content and so the tab-group have the correct content, after the rendering of velocity.

But current this don't work because tab-group macro expect to have only a tab macro in the content and currently is not able render the inner macro to see in they result to a tab macro (after the rendering of the inner macro).