javascript - How do I code an "intellisense style" interface in Angular 2+ -

i writing formula builder function in survey system i.e. survey system lets user design , create survey, rendered , captured users.

part of formula builder user creating survey can create self-answering question, indicate result of formula captured answers e.g. survey.id 555 question.id 10 plus survey.id 333 question 5.

what want achieve intellisense style interface (similar say, hipchat, when type @ , auto overlays list of users select).

an example of how user defines formula such:

"#111 * (#333 + #222) / #444 #444 not = 0 , #111 > 0" 

in above # represents question captured survey , number database id question, however, user needs know these ids (which not practical). is: when # keyed-in open intellisense list (relative cursor position) captured surveys, select one, type in period (.) brings list of questions survey selected (again intellisense style) , select relevant question.

i have looked @ using html description list overlays in angular don't seem meet requirements.

any pointing me in direction appreciated. in advance.