Terrorist groups - home based:
Islamic Revolutionary Guard Corps (IRGC):

aim(s):  protect Iran’s Islamic Revolution; spread Shia influence; internal security, including border control, law enforcement, and suppressing domestic opposition; controls country’s missiles and rockets; influence Iran’s politics and economy
area of operation(s): headquartered in Tehran, throughout Iran (2019)
Islamic Revolutionary Guard Corps - Qods Force (IRGC-QF):

aim(s): protect Iran’s Islamic Revolution; spread Shia influence; conduct clandestine overseas operations, often supporting other terrorist organizations (including Sunni groups like the Taliban when their goals align) with significant funding, logistics, training, or weaponry to commit terror attacks, either directly or through proxies; recruit, train, and equip foreign Islamic revolutionary groups throughout the Middle East
area(s) of operations: headquartered in Tehran (2019)
Jaysh al Adl:

note(s): formerly known as Jundallah

Terrorist groups - foreign based:
al-Qa'ida (AQ): aim(s): unite the worldwide Muslim community, overthrow governments perceived as un-Islamic, and, ultimately, establish a pan-Islamic caliphate under a strict Salafi Muslim interpretation of sharia (2018)
Kurdistan Workers' Party (PKK): aim(s): advance Kurdish autonomy, political, and cultural rights in Iran, Turkey, Iraq, and Syria
area(s) of operation: operational in the northwest; majority of members inside Iran are Iranian Kurds, along with Kurds from Iraq, Syria, and Turkey (2018)