Hello everyone. I too want this feature integrated into OBS, but as a developer I can attest to the difficulty in developing things of this nature and finding the right release to add this to. It is not as simple as seeing a demand and cranking it out. There are so many existing planned features that came before this as well as unplanned features (AKA bugs) to address.
While we patiently wait I have discovered a workaround that I was able to implement today. Here is what is required.
Download the lite version of virtual audio cable and install it. (
https://vac.muzychenko.net/en/download.htm)
Set the audio that you want to export to also go to the monitor
Set the monitor to be the virtual line that VAC created.
In the application that you want to hear the OBS "Virtual Mic" in set the mic to be the same virtual line that you set as the monitor
Enjoy and be patient.