Luck me! I've been given a 3 position hoop for my machine. I have a max:embroidery field of 5 x7. Has anybody any ideas how I use this hoop and where I can find designs for it please?

I have never tried a split design for hoops and that my be what you are thinking of. I have used 3 position hoops in another way. Say I want to do a long large word like CHRISTMAS (10 inches long) but only 4 letters will fit in my regular hoop. I draw a removable/washable line to line up the letters then I do the first 4 letters or how many will fit in the design area. I put the next letters in the machine and move the hoop to the next area carefully ling up the new letter to the first letters and so on. You will get better results than rehooping and trying to line it up.
This also works for announcements and memory designs. I put a baby design on the top of the hooping area, move it to the next area and do name, birthdate, weight, etc., move to the next area and do another design. If necessary I rehoop for corner accents depending on how creative I'm feeling.

It sounds like the Plus hoop for the earlier husqvarana machines. If so you need designs that are divided into the three sections and load each section separately as you reposition the hoop for that part of the design. There were some free ones out there a few years ago. Maybe google plus hoop free designs and see if you come up with any. Good luck.