How to add "Other Works" menu inside header for portfolio posts?
1. Create sidebar via theme settings admin -> general -> sidebars e.g called ''single portfolio sidebar" and save theme settings!
2. Go to wordpress menu page and create new menu e.g called "other works" and add as many single portfolio items tothis menu as needed - single portfolio posts should be displayed inn one of boxes on the left side - if not please use screen options at the top right corner to make it visible. After that save menu.
2. Go to wordpress widgets page and drag and drop Custom Menu Widget into newly created sidebar "'single portfolio sidebar". Choose which menu to display -> in this case it will be "other works" menu.
3. Create new portfolio or edit existing ones ( each one individually ) and search for Primary Sidebar settings in Page Appearance box -> assign "single portfolio sidebar" -> save and publish