Hello College Dawson,
Thanks for reaching out to us with your question.
If you would like to modify the urls of said buttons you can use the tribe_get_previous_month_link
filter. Something like this:
function change_past_month_link( $html ) {
$html = $html . "&custom-taxonomy=custom-value";
return $html;
}
add_filter( 'tribe_get_previous_month_link', 'change_past_month_link' );
Note that I haven’t tested this but this is the principle.
The filter for the next month is “tribe_get_next_month_link”.
Let me know if this helps.
Cheers,
Andras