Hi,
1. Globals are not going to be deprecated in PHP 7 and there is little/no chance that it will ever happen.

2. Since the code is not complete, I can not guess how you are taking the details from the user.

I am sorry but I am not available for hire at the moment due to my commitments with BuddyDev work. But, Your task seems easy enough to me and you do not need to hire me to get it completed.

Please send me the code on brajesh@buddydev.com and I will send you the updated one. This seems to be small functionality that should not take much time.

Thank you Richard.
It will be helpful for not only MediaPress but other plugins too that adds nested pages on user pages.
Thank you for posting it here, It will certainly help others too.

Regards
Brajesh

Hi,
Have you tried this

function my_custom_subnav() {
	global $bp;
        global $collection_term;
	$collection_term_slug = preg_replace('/\s+/', '-', $collection_term); // replace spaces with hyphens.
	  $collection_term_slug = preg_replace('/[^A-Za-z0-9\-]/', '', $collection_term); // Removes special chars.
	$screen_function_name = 'subnav_function_to_show_' . $collection_term_slug;
	

	bp_core_new_subnav_item( array( 
		'name' => $collection_term,  
		'slug' => $collection_term_slug,  
/* rest of the code */

and make sure that you initialize $collection_term before making a call to

my_custom_subnav()

That should work. Can you please give it a try. If you are initializing $collection_term in another function, then declare it global there too. Also, It must be initialized before call to the function.

Thank you Richard.
You are right about the cause. I am glad you found it. BuddyPress dynamically replaces actual content with the generated content( and in this case WordPress was regenerating excerpt based on that generated content). the_content() is the right function.

use bp_is_user() for conditional testing since it will fix problem with other plugins too.

Hope that helps.

This code is fine.
As far as I checked on the site, activating other themes make this work but when I reactivated your theme, the page went away.

So, It is confirmed that it is some modification in the theme causing this.

Can you please think of any such modifications in your functions.php? or can you please activate the parent theme and see if that works?