Complex sentence: As of 2011, the provincial capital is Imus City, but most of the provincial offices are in Trece Martires City--making Trece Martires as a "de facto" capital of the province, while Imus as a "de jure" provincial capital.
Split into simpler sentences: As of 2011, the provincial capital is still Imus City, but most of the provincial offices are still located in Trece Martires City. Thus, making Trece Martires as a "de facto" capital of the province, while Imus as a "de jure" provincial capital.