Assuming you’ve worked through Mignola’s other comics, BPRD, Joe Golem, Witchfinder, Lobster Johnson, Amazing Screw-on HeadHead, etc:

Hellblazer - classic occult detective comics

Damn Them All - like a female John Constantine

Caballistics Inc - team who investigate supernatural mysteries, Mignola-esque art

Absalom - actual police detective who investigates demons over-stepping the agreed upon line. Same other as the above and Mignola adjacent art

Necronauts - same author again, about a team of real-life figures drawn together to investigate Lovecraftian cults

Charles Fort, Prophet of the Unknown - similar concept (with Fort and Lovecraft as characters) and the same artist

Devlin Waugh - camp, vampire occult detective in the Judge Dredd universe. The first volume has a number of shorter stories that get you into the fictional setting then the big story drops in the second volume

MI-13 are the group investigating British weirdness in the Marvel Universe - see Paul Cornell’s Wisdom (if nothing else) and Captain Britain & MI-13

Some iterations of the Howling Commandos do something similar - Nick Fury’s Howling Commandos and Howling Commandos of S.H.I.E.L.D.

Later series of Marvel Zombies (3 onwards) have a team that works to stop the zombie menace

You’ll find similar teams at DC bringing together magical superheros and monsters - Shadowpact and, more recently, Justice League Dark. Creature Commandos previously did something similar and looks to be meaning into this under James Gunn.

While we are looking at DC, Sandman is always a solid recommendation. As might be other Gaiman series - the Dead Boy Detectives, The Trenchcoat Brigade, The Books of Magick.

The Doom That Came to Gotham - Mignola’s Elseworld mix of Batman and Lovecraft. See also: Gotham by Gaslight

The DC Universe by Mike Mignola - collects various DC outings, especially his run on Superman

Cosmic Odyssey - Jim Starlin trying to do Cosmic stories, similar to his Marvel ones, with Mignola on art duties