Pulled info from different sources and combined them so hope this solution helps...
To do this, we will have to get three different dresses each for Tifa, Aerith, and Cloud.
You will need to do the same chapters (3 to 9 for Tifa) an additional two times via Chapter Select to get all of the dresses for each person.
How to Get Tifa’s Dresses
In Chapter 3, you’ll arrive in the Sector 7 slums where Tifa will show you around. A special cutscene between Tifa and Cloud can be accessed after completing all of the different side quests here. Tifa wants to go out on the town and will ask which dress would suit her, and the options are:
This is the dress from the original and if you do no side quests.
It looks kind of like a Black Chun-Li outfit.
The exotic dress looks like a kimono.
What you choose here determines which dress Tifa wears when seeing Don Corneo in Chapter 9.
How to Get Aerith’s Dresses
Next, Aerith’s dress options are in Chapter 8. The dress she will wear is determined by how many side quests get completed in the Sector 5 Slums. Completing all six quests results in her wearing the best dress, completing three quests results in her wearing an average dress, and doing none of them gets the most basic dress.
How to Get Cloud’s Dresses
In Chapter 9, when you go to Don Corneo’s mansion you’ll find Johnny running away. Talking to him will unlock Burning Thighs, A Dynamite Body, and The Party Never Stops which will reward the Blue Corset Dress.
The Purple Dress can be accessed by ignoring Johnny completely and paying for the most expensive hand massage from Madam M. The quests Burning Thighs, The Price of Thievery, and Shears Counterattack will become available.
Cloud’s final dress can be obtained simply by completing none of the side quests and going to the mansion directly from Madam M’s. This is how you get the Maids Dress.
(below taken from PowerPyx for ease)
You can pick the chapters specifically or do them while doing other trophies in 3 playthroughs as follow...
Chapter 3 (Tifa): Pick Sporty (did all side quests)
Chapter 8 (Aerith): Do all side quests
Chapter 9 (Cloud): Do first set of side quests The Party Never Stops, A Dynamite Body, Burning Thighs
Chapter 3 (Tifa): No side quests (will automatically pick Mature)
Chapter 8 (Aerith): Do 0 side quests
Chapter 9 (Cloud): Do 0 side quests
Chapter 3 (Tifa): Pick Exotic (did all side quests)
Chapter 8 (Aerith): Do 3/6 side quests
Chapter 9 (Cloud): Do second set of side quests The Price of Thievery, Shears’ Counterattack, Burning Thighs