Kindly check below stated link by bitdefender support staff
https://www.bitdefender.com/consumer/support/answer/13353/
As per the mentioned link, you can only add websites URL under split tunneling feature.
Regards
Hi @JohnB68,
The above screenshots are not yet updated, as the developers recently launched a VPN update that includes split tunneling for apps as well. I have addressed this matter and the relevant article will be updated shortly.
In the meantime, the feature should look like this:
Click on the Add picklist, select Application and then browse the computer for the app you wish to add:
Let us know how it goes.