How can a user find posts he/she has created in this community discussion db?
If you look top right on your screen, you will see your picture (avatar/icon). Click on that then select 'Profile' from the dropdown menu that appears. NB: If you right-click on 'Profile' and select 'open link in new tab' you'll be able to keep this page open to follow the instructions...
That will take you to your profile.
There, top left of that page, click on 'Activity', second entry to the right of your icon...
On the next page that appears, you'll see the headings and links to the posts that you have created and responded to.
Hope this helps,
All the best,