1. Open up Processing toolbox


2. Search for Subdivide tool


3. Run Subdivide tool on the complicated AOI. Adjust and play with the “100000” value to change the number of split features that will be more suitable to use.

a. You will get a Subdivided temp layer with a singular split, multipart feature. Use this as input for the next tool

4. Search for Multipart to singlepart tool from Processing toolbo

5. Run Multipart to singleparts tool on the Subdivided temp layer.

a. You will get a Single parts temp layer with each split feature as its own record

6. Export Single parts temp layer to a new GeoJSON or Shapefile.

Ensure Geometry type = Polygon and Force multi-type = unchecked