Hi there, I am also a Japanese learner.
I hope you don't mind me sharing the below with you. I may not be correct entirely, so please read with caution.
見せられるtakes the passive from. You are probably correct to say is 给谁看 or 向谁展示.
この教科は多くの人に見せられる (This subject is shown (向大家) to many people)。
寿司が誰かに食べられた！（The sushi was eaten by (给谁吃了)somebody!)
On the another hand, 見させられる is a causative passive form usually used when compelled to do something(被迫做某事的感觉).
彼女は私に恐ろしい映画を見させられた(She made me (她强迫我) watched the horrible movie)
仕事を辞めさせられた (I was forced (我被逼) to quit my job.)。
Just my 2 cents worth.