Add a line specifying the directory to TEST.ROOT
TestNG.dirs = dir1 dir2 dir3 ...
Include the package root directory for each group of TestNG tests, and specify the package root directory relative to the test root directory.
You can also override the value in TEST.ROOT by using the TEST.properties file in any subdirectory of the test root directory that contains the package root. If you put the declaration in a TEST.properties file, you can specify the path relative to the directory containing the TEST.properties file. In particular, instead of declaring the directory in TEST.ROOT, you could place the declaration in a TEST.properties file in the package root directory for the group of tests, in which case the declaration would be simply:
TestNG.dirs = .