This filter is found in the image window menu under Filters->Map->Small Tiles.
This filter reduces the image (active layer or selection) and displays it in many copies inside the original image.
Figure 11.169. “Small Tiles” filter options
1/(2*n) means "the image into 2*n tiles" where "n" is the number you set with the slider or its input box. n = 3 will make six tiles in the image.
With this slider and its input box, you can set the opacity of the resulting image. This option is valid only if your image has an Alpha channel.
You can flip tiles according to the Horizontal or/and Vertical axis by checking the corresponding option(s).
You can also decide which tiles will be flipped:
All tiles: no comment.
Alternate tiles: only odd tiles will be flipped.
Explicit tile: you can define, a particular tile by using both Line and Column input boxes. This tile will be marked with a box in Preview.