Published as Op. 108, this is perhaps Wagner's most substantial standalone piano work. It is a highly expressive, song-like piece that bridges the gap between salon music and genuine character study.
The main challenge is maintaining a sustained melodic line over a complex, shifting accompaniment pattern.
Comparable difficulty and character — good candidates for what to learn next.
Albumblatt für Frau Betty Schott (Op.108) is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 7.
You should be comfortable at Henle level 4 — meaning you can already play level 3–4 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
A typical performance of Albumblatt für Frau Betty Schott (Op.108) lasts about 4 minutes.
Albumblatt für Frau Betty Schott (Op.108) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.
Pieces at a comparable difficulty and character include Albumblatt für Frau Betty Schott, WWV108 by Wilhelm Richard Wagner, Berceuse by Georges Bizet, Berceuse sur le nom de Gabriel Fauré by Maurice Ravel — see the full similar-pieces list on this page.