Is there a way to have separate docks per display? I'm using Yosemite. I have 2 displays (each with its own space and both have the dock) and I have a application (app1) with various windows. These windows are distributed between these two displays: I have some of them in display 1 and some of them in display 2. 

The problem is that: when I'm in another application (not app1), if I click the app1 icon in the dock, its windows are all activated in all displays (no matter in what display I clicked app1 icon in the dock).

What I want is: when I click app1 icon in the dock, activate the windows that are only in the active display. For example: suppose that none of app1 windows's are activated; if I am in display1 and click app1 icon in display1 dock's, only app1 windows that are in display1 are activated (keeping whatever was in display2 as it was).

You may also replace every reference I did to 'display' to 'space', because I'm using separate spaces per display. I saw a very similar (and old) post where people recommended DockSpaces, but I can't find this application anymore.

Any suggestions?
I do not have the Yosemite but on Mavericks works as follows:


  The trick is to assign a second Space to the desktop. You do that by
  pressing the Mission Control button on your Mac keyboard (F3) or
  whatever you've assigned in System Preferences > Mission Control, and
  moving the mouse to the upper right of the display until you see a
  Plus (+) icon. Click it to create a new Space.


After you've created a second Space, your dock option will change. Now you'll see this:



Now you can assign the app to the Desktop of your choice, typically either the desktop on display #1 or display #2.