snuji -nuj- gismu

x1 is a sandwich/layering [not restricted to food] of x2 sandwiched between x3.

See also midju, nenri, sepli, senta, jbini, bitmu, sruri.

In notes:

bitmu
x1 is a wall/fence separating x2 and x3 (unordered) of/in structure x4.
jbini
x1 is between/among set of points/bounds/limits x2 (set)/amidst mass x2 in property x3 (ka).
midju
x1 is in/at the middle/center/midpoint/[is a focus] of x2; (adjective:) x1 is central.
nenri
x1 is in/inside/within x2; x1 is on the inside/interior of x2 [totally within the bounds of x2].
senta
x1 is a layer/stratum [shape/form] of x2 [material] within structure/continuum/composite x3.
sepli
x1 is apart/separate from x2, separated by partition/wall/gap/interval/separating medium x3.
sruri
x1 encircles/encloses/is surrounding x2 in direction(s)/dimension(s)/plane x3.
djasnuji
s1=c1 is a sandwich (food) with s2 sandwiched between s3, edible for c2.
sanduici
x1 is a sandwich with x2 sandwiched between x3