Creating arrow plot with tikz

Question

How can I make with tikz in latex, something like in the following plot?

Do you have any reccomendation where to search anything like this in overleaf or maybe if someone could tell me what commands to work with?

Answer 1

Here is solution for your first question on texSE. The package calrsfs is needed to get the symbols C and I.

\documentclass[tikz,border=5mm]{standalone}
\usepackage{calrsfs}
\begin{document} 
\begin{tikzpicture} 
\path 
(0,0) node (i) {$i$}         
(0,1.5) node (G) {$G$} 
(2.5,0) node (C) {$\mathcal{C}$} 
(-2.5,0) node (I) {$\mathcal{I}$} 
; 
\begin{scope}[>=stealth,nodes={scale=.6,magenta}]
\draw[->] (i) to node[right]{$F^i\left(x^i_{\mathcal{I}},y^i\right)$} (G); 
\draw[->] (i) to node[above]{$t^i$} (C); 
\draw[<-] (i) to node[above]{$x^i_{\mathcal{I}}$} (I); 
\draw[->] (C)--++(0,-1)-|(i) node[above,pos=.25]{$y^i$};
\end{scope}
\end{tikzpicture} 
\end{document}

Answer 2

Here is an attempt with tikz-cd:

\documentclass{article}
\usepackage{tikz-cd}
\begin{document}
\begin{tikzcd}[row sep=large, column sep=large]
  & A\\
  B\ar[r,"x"] & C\ar[r,"y"]\ar[u,"z"']\ar[d, phantom, ""{coordinate, name=Z}]
  & D\ar[l,"w"{pos=0.75},to path={
      -- (\tikztostart.south)
      |- (Z) \tikztonodes
      -| (\tikztotarget.south)
      -- (\tikztotarget)
  }]\\
  & {}
\end{tikzcd}
\end{document}