Want to collapsed the particular column in grid

Hi All , 

I am using a a!gridField , in that one column is there having multiple values . I just want to make taht particular field based on show more and show less . so that it shoould not be conjusted to see . 

a!gridColumn(
label: "Decom Site(s)",
sortField: "siteids",
value: substitute(fv!row.sites, "|", char(10)),
align: "START",
width: "MEDIUM"
),

fv!row.mob contains 

AA000000

AAAAAAA

AAAAAA

AAAAAA

AAAAAA

AAAAAA

AAAAAA and many more 

Thanks in Advance