Aruch HaShulchan, Laws of Tzedakah 249:8

Our Rabbi the Rama wrote, “one can’t use money set aside for the tithe to purchase a mitzvah-related object, such as candles for the synagogue or another mitzvah-related object. He can only give from the tithe to the poor.” But it is permissible to use the money set aside for the tithe to be a godfather and thus to provide for a new mother, or to pay for the circumcision ceremony when the father is poor, or to support a dowry for a poor bride, or other such things--all of these are permissible uses of tithe (Shach 249:3). Similarly, one who purchases an aliyah to the Torah and therefore makes a donation to the Beit haMidrash, this may be from the tithe. And likewise, all that is given as charity to the attendants of the community: these are definitely considered tzedakah. [translation by AJWS]