Easy way to do this?

explain more in details

create buffer1 and buffer2 for example:
buffer1=createimage(graphicswidth(),graphicsheight())
buffer2=createimage(graphicswidth(),graphicsheight())
(note that you MUST use the transparent color of your tileset as background color of the buffer2)
the you draw your map layers in these buffers

layer 0 and 1 in buffer1
layer 2 and 3 in buffer2

so your main loop can look like this

repeat
drawblock buffer1,0,0
*** draw the player ***
drawimage buffer2,0,0
flip
until keydown(1)

so no need to redraw the map from the data each frame :)