How to translate headers; using language file,

1) I already have a translation of the whole buddy press application. The website you suggested

https://wpmudev.com/blog/basic-guide-to-creating-a-buddypress-language-file-for-sitewide-label-and-message-editing/

asks me to do what I already had done. Instead of me manually changing the buddypress/bp-languages/buddypress.pot file I already found and uploaded the Spanish version of BP in to this folder:

buddypress/bp-languages/buddypress-es_ES.mo

perhaps what I need to do is change this code?

Next step is to call the buddypress-mysite.mo file from wp-content/plugins/bp-custom.php like so:

define( ‘BPLANG’, ‘mysite’ );

if ( file_exists( BP_PLUGIN_DIR . ‘/bp-languages/buddypress-‘ . BPLANG . ‘.mo’ ) ) {

load_textdomain( ‘buddypress’, BP_PLUGIN_DIR . ‘/bp-languages/buddypress-‘ . BPLANG . ‘.mo’ );

}

However, I am unable to find the wp-content/plugins/bp-custom.php file in my files?

HELP please

2) please explain what each are for:

1. BuddyPress Spanish Language .mo file

2. Corporate BP theme language .mo file

3. buddypress/bp-languages/buddypress.pot

Don’t you think that #1, should take care of my issue? I obtained the file from http://www.bp-es.com/noticias/descargas/ and placed it in

/wp-content/plugins/buddypress/bp-languages/

Why are there three files to change the language? And what parts of the “front end” does each file change?