You should be able to get the current logged in user ID and then use pre_get_posts to alter the main query on the home/blog page to only show posts from that specific user. As I understand, you are talking specifically about authors.
You might want to also check the user's capabilities as well as simple subscribers won't see any posts on the blog/homepage as they can't author posts.
A very simple pre_get_posts action will look something like this: (NOTE: The following is untested)
add_action( 'pre_get_posts', function ( $q )
{
if ( is_user_logged_in() ) { // First check if we have a logged in user before doing anything
if ( $q->is_home() // Only targets the main page, home page
&& $q->is_main_query() // Only targets the main query
) {
// Get the current logged in user
$current_logged_in_user = wp_get_current_user();
// Set the logged in user ID as value to the author parameter
$q->set( 'author', $current_logged_in_user->ID );
}
}
});
EDIT
From comments, it seems that each user has a category with the same name and this specific category is then attached to a post
To accommodate this, you will need to do the following
As above, get the current logged in user
You will then need to use the info from the current user which will match up to the category. For instance and as an example, if 'display_name' == 'category name', then, if the user display name is Jane Doe, then the category name assigned to the name will also be called Jane Doe
In the above example, we need to get the category by name so that we can get the category ID. We will be using get_term_by() which can be used with build in taxonomies like category or custom taxonomies
We can then go ahead and do the same as in the original answer
You can do something like this; (I have commented the code so you can understand and follow it better)
add_action( 'pre_get_posts', function ( $q )
{
if ( is_user_logged_in() ) { // First check if we have a logged in user before doing anything
if ( $q->is_home() // Only targets the main page, home page
&& $q->is_main_query() // Only targets the main query
) {
// Get the current logged in user
$current_logged_in_user = wp_get_current_user();
/**
* We will now get the term/category object from the user display_name
* You will need to make sure if this corresponds with your term/category
* If not, use the correct info to match
*/
$term = get_term_by(
'name', // We will get our term by name as term name == user display_name. Change as needed
$current_logged_in_user->display_name, // Our value to look for will be user display_name
'category' // The taxonomy the term belongs to. category is the build in taxonomy
);
if ( $term ) { // Only filter the main query if we actually have a term with the desired name
$q->set( 'cat', $term->term_id ); // Filter the posts to only show posts from the desired category
}
}
}
});
