Using commands to create custom achievements that worked prior to 1.9 worked with selector. The following command does not display in 1.9 but works in 1.8.9. Players do not get displayed in the chat.

/execute @a[score_RecAchievement=0,score_RecAchievement_min=0,score_Recording=2,score_Recording_min=2] ~ ~ ~ tellraw @a {"text":"","extra":[

{"selector":"@a[score_RecAchievement=0,score_RecAchievement_min=0,score_Recording=2,score_Recording_min=2]"}

,

{"text":" has just earned the achievement",color:white}

,{"text":" [YouTuber!]","color":"dark_purple","hoverEvent":{"action":"show_text","value":{"text":"","extra":[

{"text":"Record for your first time."}

]}}}]}

Hope this helps