Apply gradient to multiple objects

[freshpipes]

I am trying to apply a gradient so that these circles fade out at the bottom.  There are several paths with different line weights and opacities and I cannot overlap a gradient of the background color over top of these to fade them out.  Is there a way to maybe "flatten" these together holding their opacities and apply a master gradient so that they fade?

[Monika Gause]

I'm not quite sure how you want this to look like. Does it work when you make them into a compound path?

[Jacob Bugge]

freshpipes,

As I (mis)understand it, you can:

1) Select all circles that are not overlapping along with one of the circles within each overlapping pair (top left and middle right, you can choose the one to the right) then Ctrl/Cmd+G to form a Group, then select the other circle in each overlapping pair (then left one) then Ctrl/Cmd+G to form a Group;

2) Select both Groups and Ctrl/Cmd+C+F+X+F to bring the copy Groups to the front, then Object>Path>Outline Stroke to turn them into filled rings, then set the Opacity to 100%, then apply a 90 degrees Linear Gradient;

3) Select each set of corresponding Groups and in the Transpareny palette (flyout) click Make (Opacity) Mask with Invert Mask ticked.

That ought to give you fading out at the bottom for every circle without interfering with the overlaps and other aspects of the appearance(s).