\documentclass[a4paper,twoside,openright,12pt, draft]{book}
\usepackage{filecontents}
\usepackage[
    %automake=immediate,
    %automake,
    nomain, 
    nosuper, abbreviations, symbols, toc=false, 
    %record=alsoindex% create group field and other stuff
    record,
    stylemods={list,tree,topic,longextra,longbooktabs}
]{glossaries-extra} % for nomenclature

% Correct topic style
\makeatletter
\newglossarystyle{correctedtopic}{%
    \setglossarystyle{topic}% base this style on the topic style
    \renewcommand*{\glstopicAssignSubIndent}[1]{%
        \parindent\dimexpr##1\glstopicSubIndent-\glstopicSubIndent\relax
        \glstopicAssignWidest{##1}%
        \hangindent\dimexpr\parindent+\glstopicwidest\relax
    }%
    \renewcommand*{\subglossentry}[3]{%
        \ifnum\glstopic@prevlevel=0\relax\glstopic@prechildren\fi
        \def\glstopic@prevlevel{##1}%
        \glstopicAssignSubIndent{##1}%
        \glstopicSubItem{##1}{##2}{##3}%
        \par%
    }%

}
\makeatother

\begin{filecontents}{terms.bib}
    % Encoding: UTF-8
    @indexplural{feat,
    text  = {Feature vector},
    topic = {symbol}
    }
    @indexplural{imaging,
    text  = {Image},
    topic = {symbol}
    }
    @symbol{featvec,
    name        = {\ensuremath{x_j}},
    description = {a feature vector of  identifier ID representing an image from a subset $D'$},
    identifier  = {feat}
    }

    @symbol{featvecset,
    name        = {\ensuremath{X}},
    description = {a set of feature vectors from a identifiering task},
    identifier  = {feat}
    }

    @symbol{labelfeatvec,
    name        = {\ensuremath{y_j}},
    description = {a feature vector of label features representing an image from a subset $D'$},
    identifier  = {feat}
    }

    @symbol{labelfeatvecset,
    name        = {\ensuremath{Y}},
    description = {a set of feature vectors from a labeling task},
    identifier  = {feat}
    }

    @symbol{nuhuman,
    name        = {\ensuremath{\nu_h}},
    description = {an attribute of a feature vector representing ID from each human identification task},
    identifier  = {feat}
    }

    @symbol{img,
    name        = {\ensuremath{n}},
    description = {an image},
    identifier  = {imaging}
    }

    @symbol{imgsize,
    name        = {\ensuremath{N}},
    description = {image size},
    identifier  = {imaging}
    }

    @symbol{imgset,
    name        = {\ensuremath{{H}}},
    description = {a set of images},
    identifier  = {imaging}
    }

    @symbol{imgsubset,
    name        = {\ensuremath{I'}},
    description = {a subset of images},
    identifier  = {imaging}
    }
\end{filecontents}

\GlsXtrLoadResources[
  src={terms.bib},
  field-aliases={identifier=parent},
  selection={all},
  save-locations={true},
  type={symbols},
  set-widest
]

\begin{document}
\setglossarystyle{topic}
\printunsrtglossary[type=symbols]
\end{document}