BuddyPress.org

a:3:{i:0;s:7:”English”;i:1;s:4:”Math”;i:2;s:10:”Substitute”;}
is a serialized array.

BuddyPress will unserialize profile data via
xprofile_get_field_data( $field, $user_id = 0, $multi_format = 'array' )
and return an array.

But if you want to do this in the context of a search query, you probably want to use wildcards in the mysql statement, for example: %math%.
This can be tricky to implement if you haven’t done it before.

There is already a good plugin that does member searches based on profile field values:
https://wordpress.org/plugins/bp-profile-search/