I am trying to apply a pattern piece of vector artwork which is from one image to another image.

The original image has the following:

![enter image description here](https://i.stack.imgur.com/9HDTs.png)

it has a clip group - with a clipping path and a artwork splatter layer - which contains a splatter set of artwork seen - which extends far beyond the faded purple rectangular outline you can see - but doesnt show because of the clipping path.

I want to recreate this - on the following image.

In this I have the following:

![enter image description here](https://i.stack.imgur.com/WBIa2.png)

I have a group which contains a path - which is the blue rectangular outline. I also have copied the artwork splatter layer from the file where the above example comes from into group called Splatter artwork.

I want to turn my 'path' layers in this second image into clipping masks where I can then add my splatter artwork layer inside of the clipping mask layer but I cannot work out how to do this - my paths cannot contain other layers it seems, not sure why. 

I am very new to illustrator - so please help. I hope you understand the problem my explanation is probably pretty bad - but basically I want to emulate the clipping mask outline of the path as per the first shape in the first example - in my second image - the rectangular shape is subtly different hence why I need to do this.