Regex Tool usage – Alteryx Community

daHi All please help me to find out the desired output only through REGEX tool. There are 5 questions that I am struggling with.

1	Required : Only last two letter of string.			4	Required :	where AF in the last pick “AF” and if Diff is at start then pick “Diff”
		Input	Output				Input	Output
		City	City				Category	Category
		Delhi	hi				London_File_AF	AF
		Mumbai	ai				Diff_London_File	Diff
							UK_File_AF	AF
2	Required :	Only required first and last word of string					Diff_UK_File	Diff
		Input	Output
		Category	Category		5	Required :	Delimeter split (_)
		Zebra Crossing Republic	Zebra Republic				Input	Output
		John Smith Crossing	John Crossing				Category	R1	R2	R3
							London_File_AF	London	File	AF
3	Required :	Only required last word of string					Diff_London_File	Diff	London	File
		Input	Output
		Category	Category
		Zebra Crossing Republic	Republic
		John Smith Crossing	Crossing