How will I force user to complete their profile before performing any action on the site in order to make the matchmaking perfect
or how can I split the registration page to nested tab so that the field with not be too long for the users…
Unfortunately, it is not possible to split the registration process in multiple steps by default with BuddyPress and to our knowledge, there is no plugin that you could install to add this feature to your website. Also that kind feature is part of the “plugin territory” and is not a feature that we can implement in the theme.
To go further, you will have to require custom development work.
You're trying to setup your theme but you're experiencing errors when importing the demo content? Or you've just followed the setup guide but your website doesn't look exactly like our demo? These are common issues for which you can find easy and quick fixes.