new blog template not showing themes on Specified page


I am using pro sites with new blog template. I have 3 levels and themes are assigned for each levels particularly. But New blog template is over riding the pro sites settings. I wanted to remove select this theme on previewer. If I could remove that only theme demo will be present and users can only see demo.Now after they create their account themes created using blog templates will be there so that they can use customized one. Please help me to remove “Select this theme” option on theme previewer.