Contents of the blog posts are held in the body column in the jiveblogpost table, you should be able to filter the blog posts based on the userid of the users.
If you specifically wanted to filter only the personal blog posts, then you will have to identify corresponding the blogid from the jiveblog table. Again, you should be able to identify the blogid based on the name and containertype(would be 2020 for Personal Blog) columns. Below are the constants of the column containertype,
- 2020 - Personal Blog(UserContainer)
- 700 - Social Group blog
- 600 - Project blog
- 14 - Space blog
Here is the Application database schema for your reference.