When you installed the project the first time you did
git clone email@example.com:incardon/openfpm_pdata.git
The created openfpm_pdata folder is the OpenFPM source folder. During installation you also did the following
./install -i "/OpenFPM/dependencies/directory/" -c "--prefix=/OpenFPM/installation/directory/"
The folder that you gave to the install script with the -i option is the OpenFPM dependencies directory
The folder that you gave to the install script with the -c "--prefix=" option is the OpenFPM installation directory