I saw this earlier, but nobody has replied... so here goes!
client 1 has been a visitor in 2014 and 2015 = blank
this is easy enough, using IF statement, something like this -
if YEAR([date]) = 2014 and [type] = 'visitor' then null
elseif YEAR([date]) = 2015 and [type] = 'visitor' then null
the problem is...this part
client 2 has been a visitor in 2014 and become exhibitor in 2015 = V to E
client 3 has been an exhibitor in 2014 and became visitor in 2015 = E to V
how to explain...?!
if i had to do this (id prefer to do in SQL), i would first want to create buckets, and then test against those...
i.e. i would want to list all vistors in 2014, and separately visitors in 2015 etc.
then i would nest these as a sub-query to identfity who has changed across years
it maybe possible in tableau but needs to thinking about, you may be able to do it via bins, but i would do this outside tableau, as mentioned in SQL or something
Apologies, not entirely helpful, hence me waiting on others... but hopefully something there provides some inspiration
happy to try and help further if i can...
Can you provide some fake data please ?
Is your dataset purely Name, Year, Type ?
Do you have Event as well, is in several different events in the one year, or is Event really Year ?