I have an idea to filter library by comment tag. I place there info like that: (2005) (Single) Release Name, it helps me to show albums by year (3rd point in main menu). But I also want to filter it by release type (single, live, ep, etc), second point in main menu ("Album Artist Type") is working, but first one not. Can't understand why can't I first sort by albumartist and then choose from release types for it.
#! rockbox/tagbrowser/2.0
%menu_start "aa_custom_types_test" "Album type"
"Albums" -> comment ? comment !~ "(Single)" & comment !~ "(Compilation)" & comment !~ "(EP)" & comment !~ "(Live)" -> title = "fmt_title"
"Singles" -> comment ? comment ~ "(Single)" -> title = "fmt_title"
"Compilations" -> comment ? comment ~ "(Compilation)" -> title = "fmt_title"
"Ep`s" -> comment ? comment ~ "(EP)" -> title = "fmt_title"
"Lives" -> comment ? comment ~ "(Live)" -> title = "fmt_title"
%menu_start "aa_custom"
albumartist ==> "aa_custom_types_test"
%menu_start "aa_custom_types" "Album type"
"Albums" -> albumartist -> comment ? comment !~ "(Single)" & comment !~ "(Compilation)" & comment !~ "(EP)" & comment !~ "(Live)" -> title = "fmt_title"
"Singles" -> albumartist -> comment ? comment ~ "(Single)" -> title = "fmt_title"
"Compilations" -> albumartist -> comment ? comment ~ "(Compilation)" -> title = "fmt_title"
"Ep`s" -> albumartist -> comment ? comment ~ "(EP)" -> title = "fmt_title"
"Lives" -> albumartist -> comment ? comment ~ "(Live)" -> title = "fmt_title"
# === Begin of main menu
# Define the title of the main menu
%menu_start "main" "Database"
"Album Artist Test" ==> "aa_custom"
"Album Artist Type" ==> "aa_custom_types"
"Album Artist Sort" -> albumartist -> comment -> title = "fmt_title"
"Album Artist Y" -> albumartist -> year -> album -> title = "fmt_title"
# And finally set main menu as our root menu
%root_menu "main"
Upd: something like
"Album Artist Test" -> albumartist ==> "aa_custom_types_test"
doesn't work too