I am using SU Pro 2015 on Yosemite on a brand new 2015 Macbook Pro 15" with dual monitors.
I would like to have the top bar and my dock on my second screen.
I have changed Mission Control Setting and turned off DISPLAYS HAVE SEPARATE SPACES which fixed an issue I have been having for years where my button pallets would not stay where I left them after each session. I then restarted, but I do not have my top bar on both screens nor do I have a dock on both screens
Alas, I don’t think you can have it both ways. The DISPLAYS HAVE SEPARATE SPACES setting determines whether each display is considered to be a separate “space”, equivalent to how you can make multiple spaces on a single display and have different app windows in each… When it is turned off, the combined area of both displays is considered to be a single space showing a singe desktop. Your button pallets stay put because from the OS point of view, there is only one desktop space. You will also find that you can move windows so that they are partially on each of the displays. However, with this setting, the top menu and dock will only appear on one display because they only appear once on each desktop. I also don’t think there is anything SketchUp can do about this, as it is a Mac OS X setting, not an app behavior.