What AEM Version are you using?
I have followed the following steps:
Class BlogUserProfileComponentFactory.java extends
where prioriry mentioned(300) and getSupportedResourceType also mentioned to my extended component.
2) modified userprofile.js in the extended component.
3) in system/console/configMgr AEM Communities MemberUserProfileOperationService i have added custom fields in property fieldwhiteList.
But still the custom BlogUserProfileComponentFactory.java is not getting called from the extended component.
smacdonald200 you have any idea?
It's a bit difficult to just read the description and comment on a problem.
I would recommend you to :
1. First look at a working extension sample  and compare your code against it.
2. If you still can't get it working, I would request you to open a day care request, asking for help and share your code there for us to have a look.
Hope that helps!
I have followed the above mentioned link.
Daycare has been raised and code shared.
gurjeets Yes, I have got it and while I have requested the information, there seems to be some gap in developer's understanding of overlay, extension. I would encourage you to share the documentation about it, with the team(IIRC, I shared it on some other thread too)
ratnas36565562 - There seems to be some fundamental gaps in the implementation and the code sample shared. I am sharing the next step with support. Please follow them.
Also, let's close this thread, since daycare ticket has been raised.