There are two interpretations for how to play this. In order to explain it, I'll use the ultra-complex example -
Two dwarves fighting two orcs.
Dwarf A is hasted up to 3 attacks and has an init result of 24
Dwarf B is fighting normal speed, with an init result of 15
Orc X is hasted up to 2 attacks and has an init result of 34
Orc Y is fighting normal speed, with an init result of 4
Official - Standard Rule - All hasted actions take place after the normal actions in initiative order.
In this version the attacks go:
34 - Orc X
24 - Dwarf A
15 - Dwarf B
4 - Orc Y
(2nd actions)
34 - Orc X
24 - Dwarf A
(3rd actions)
24 - Dwarf A
Alternate Interpretation - Divide your Init score evenly by # of actions, and resolve each at the appropriate time
In this version the attacks go:
34 - Orc X (1st)
24 - Dwarf A (1st)
17 - Orc X (2nd)
16 - Dwarf A (2nd)
15 - Dwarf B
8 - Dwarf A (3rd)
4 - Orc Y
My preference is the alternate version, but it adds complexity. For simplicity, go with the standard.