Android - Overlapping Adjacent LinearLayouts, Overlaying LinearLayouts

I am porting an iOS application开发者_运维技巧 so the design is pretty much out of my hand. What I have is two LinearLayouts, one with what is basically a bump (shown in pictures) that I want to overlap the second LinearLayout.

I get aesthetically what I want desire I use FrameLayout to contain the two layouts. However, here I run into two functional problems. The first, I need to be able to allow the bottom, overlapping LinearLayout which is composed of five adjacent image buttons to change size (preferably, using layout_weight). The second is anything that is in the bottom of the top LinearLayout it is hidden by the bottom LinearLayout.

When I switch to using LinearLayout, from FrameLayout to contain the two I get functionally what I want, however, aesthetically it smashes the button to fit.

Both cases are pictured. All feedback is appreciated. I am hoping to find a solution to this without designing a custom widget.

Thanks.