You can use Recode and Replace string multiple times. I don't know your data, so I'm not sure what would be the best way (I would maybe go with simple regex and if more complicated is necessary you could also do that)
Repeat this for all with their own patterns
And JMP creates you a script
// Recode column: ProductDefect
Local({dt},
dt = Data Table("Sheet1");
dt << Begin Data Update;
dt << Recode Column(
dt:ProductDefect,
{Regex(_rcNow, ".*?\d+B.*", "Back", GLOBALREPLACE),
Regex(_rcNow, ".*?\d+T.*", "Top", GLOBALREPLACE),
Regex(_rcNow, ".*?\d+F.*", "Front", GLOBALREPLACE)},
Update Properties(1),
Target Column(:ProductDefect)
);
dt << End Data Update;
);
If you don't want to do it in place,run recode without that enabled
-Jarmo